gms | German Medical Science

Background: Injecting drug users (IDUs) are at high risk of infection with HIV or hepatitis C virus (HCV). Whereas the prevalence of HCV is relatively homogenous across the European countries there are substantial differences in HIV prevalence. These differences may be explained by differences in risk factors leading to both infections. Our aim was to compare the level of specific risk factors in IDUs for HIV and HCV in European countries.

Methods: 1313 medline® references were identified using the following search terms: HIV or HCV, drug use and risk behaviours. Based on their abstracts 25 studies were included in the final analysis: studies had to be conducted in Europe and published after 1996, not dealing with IDUs in prison and assess risk factors for transmission of infections related to needle sharing and sexual risk behaviour.

Results: 25 studies fulfilled all inclusion criteria. There was a consistent strong difference in HIV- and HCV-prevalence among injecting drug users, with much higher prevalence of the latter. However, there was no correlation between the prevalence of both diseases (Spearman rho 0.4, p=0.14). The measures of risk behaviour strongly differed between studies, which made an assessment of the potentially different association between risk factors and the two infections impossible. None of the variables used in any of the studies was used in more than 6 studies.

Conclusions: Numerous studies have been performed to assess the association of risk factors with the prevalence of HIV and HCV in IDUs, but their results are not comparable due to the heterogeneity in questions used to measure risk behaviours. Future studies should use comparable methodologies across different samples.